1. Field of the Invention
The present invention relates to a light source device for performing observations such as a normal light observation in which white light is applied to a subject, and a special light observation by light having a particular wavelength (special light) to observe, for example, an observation target in a subject and relates to a subject observation apparatus including the light source device and a light source control method for controlling the light source device.
2. Description of the Related Art
There has been, for example, an endoscope as a subject observation apparatus including the light source device. The subject observation apparatus is provided with the light source device to apply, for example, the white light or special light to a subject. There has been a light source device wherein a small solid state light source is disposed at one end of an optical fiber and a wavelength converting member is disposed at the other end, output light of the solid state light source is guided to the wavelength converting member through the optical fiber, and this wavelength converting member converts the output light of the solid state light source into a desired irradiation pattern or wavelength (color). A technique of the light source device is shown in, for example, Jpn. Pat. Appln. KOKAI Publication No. 2005-205195 (Patent Literature 1). Patent Literature 1 relates to a light emitting apparatus and an endoscope including this light emitting apparatus, and discloses that excitation light generated from an excitation light source enters an optical fiber, this optical fiber guides the excitation light to an emitting portion disposed at a distal end of the optical fiber, a wavelength converting member provided in this emitting portion converts the wavelength, and the light having this converted wavelength is emitted as illumination light.
However, when the above light emitting apparatus emits a plurality of illumination light having different wavelengths, more than one emitting portion including wavelength converting members need to be prepared. Thus, in the endoscope including this light emitting apparatus, more than one emitting portion including wavelength converting members need to be prepared when, for example, more than one observation such as a normal light observation and a special light observation are performed. Therefore, the size reduction of the light emitting apparatus is difficult.